Major cellular system types include those operating according to the Global System for Mobile Communication (GSM) standard, the TIA/EIA/IS-95 Mobile Station-Base Station Compatibility Standard for Dual Mode Wide Band Spread Spectrum Cellular System (IS-95A), the TIA/EIA/IS-136 Mobile Station-Base Station Compatibility Standard (IS-136), and the TIA/EIA 553 Analog Standard (AMPS/TACS). Other major cellular systems include those operating in the personal communications system (PCS) band according to the ANSI-J-STD-008 1.8-2.0 GHz standard or those operating according to the GSM-based PCS 1900 (1900 MHz frequency range) standard. IS-95A is currently being updated as IS-95B in the document TIA/EIA-3693.
Currently, each of the major cellular system standards bodies is implementing data services into its digital cellular specifications. A packet data service specification has been finalized for GSM and IS-95A. Packet data service specifications compatible with the IS-136 and IS-95B standards are also being prepared.
A third-generation CDMA system is also being developed to provide more sophisticated and improved data services than provided by IS-95 and eventually to replace IS-95. In the proposed standard for third-generation CDMA, known as cdma2000 ITU-R RTT, it has been proposed that third-generation systems include packet data services that utilize one or more control states that a mobile station may be in when engaged in a data service. The control states are states in which a mobile station can have varying physical and logical channel configurations assigned to it, depending on the present data transmission situation. The third-generation CDMA control states are intended to be utilized when packet data services for particular mobile stations have varying quality of service (QoS) requirements.
For example, when no data has been transmitted for a certain period of time, a mobile station may transition from an active state, in which dedicated forward and reverse control and traffic channels are each maintained, to a control hold state in which only a dedicated forward control channel is maintained. The control hold state allows fast reassignment through the forward control channel and frees up system traffic channel resources. Again, after a certain period of time in the control hold state when no data has been transmitted, the mobile station may transition from the control hold state to a suspended state. In the suspended state, all dedicated channels are released and the mobile station monitors only the forward common control channel. From the suspended state, the mobile station may transition back to the control hold state if it is determined that data is to be transmitted within a certain period of time, or the mobile may transition to a null state if data is not to be transmitted within a certain period of time. Each of the control states requires the mobile station to expend a certain amount of power that depends on the type of channels assigned in that state and the time spent in that state. QoS requirements may be used to determine the time period for transitioning between control states and to determine which states are allowable for a mobile station. By defining the time periods and allowable states in a particular way, a mobile station may have faster access to channel resources and less delay in its packet application to satisfy certain QoS requirements while minimizing power consumption and freeing up system resources. While QoS requirements may be the major factor in determining the transition periods and allowable control states, basing the transition periods and allowable control states solely on QoS requirements may not be the most efficient way of controlling transitions between control states.